Shock absorber for railway car trucks



Jan. 2, 1951 5;, BATH 2,536,266

SHOCK ABSORBER FOR RAILWAY CAR TRUCKS Filed Feb. 25, 1949 I nVe n/or: ae e EDaZ h.

Patented Jan. 2, 1 951 SHOCK ABSORBER FOR RAILWAY CAR TRUCKS George E. Dath, Mokena, Ill., assignor to W. H.

Miner, Inc., Chicago, 111., a corporation of Delaware Application February 25, 1949, Serial No. 78,329

4 Claims.

This invention relates to improvements in friction shock absorbers especially adapted as snubbing devices for dampening the action of railway car truck springs. I

One object of the invention is to provide a friction shock absorber of simple design, for dampening the action of truck springs of railway cars, comprising a friction casing, a pair of friction shoes slidingly telescoped within the casing, and a rubber element for Spreading the shoes apart, wherein the shoes are carried by a follower relatively movable toward and away from the casing, one ofthe shoes being anchored to the follower for movement in unison therewith, and the other shoe being movably connected to the follower and actuated during the last part of the compression stroke of the device to move relatively to said other, shoe and follower and effect distortion of said rubber element to increase the frictional resistance during the last part of the compression stroke. 1

Other objects of the invention will more clearly appear from the description and claims hereinafter following.

In the accompanying. drawing forming a part of this specification, Figure 1 is a vertical sectional view of the improved shockabsorber. Figure 2 is a horizontal sectional view, corresponding substantially to the line 22 of Figure 1. Figure 3 is a horizontal sectional view, corresponding substantially to the line 33 of Figure 1. Figure 4- is a bottom plan view of the friction casing illustrated in Figure 1.

My improved shock absorber, as illustrated in the drawing, comprises broadly a top follower A; a friction casing B formed rigid with the top follower; a bottom follower C; a pair of friction shoes D and E slidingly telescoped within the casing B, the shoe D being anchored to the follower C; a rubber block F under compression between the shoes; and a coil spring G surrounding the casing B and bearing at its top and bottom ends on the followers A and C.

The follower A is in the form of a circular disclike plate, having the friction casing B formed integral therewith and depending therefrom. The casing B is in the form of a cylindrical tubular member, open at its lower end and partly closed at its upper end, the follower A forming the top end wall of said casing. e

As shown in Figures 1 and 4, the follower A projects laterally outwardly from the casing B, thereby providing an annular follower flange ID at the upperiend of the casing. The follower A is provided with a central opening H- therethrough, adapted to accommodate the usual centering projection, not shown, of the top spring plate of a truck spring cluster of a railway car.

The casing B has the side wall thereof inwardly thickened at its lower end, as shown most clearly in Figure l, to provide a friction shell section l2,

presenting an interior, face l3.

At the right hand side of the casing B, the friction surf-ace i3 is cut away at its inner end, as indicated at I4, so that the shoe E projects beyond the upper end of the same when the mechanism is fully expanded. The inner end of the inwardly enlarged portion of the side wall of the casing B provides a transverse stop shoulder l5 at the left hand side of the casing at the inner end of the friction surface 13, with which the shoe D has shouldered'engagement to limit upward movement of the casing B with respect to said shoe.

The side wall of the casing B at the right hand side thereof, as seen in Figure 1', is inwardly enlarged or thickened at the upper end portion of the casing to provide a luglike projection l6 for actuating the shoe E.

The bottom follower C is in the form of a cylindrical disclike plate of the same outside diameter as the follower A. The follower C is formed with an upstanding central lug IT in the form of a short cylindrical post having a laterally projecting, annular flange at its upper end forming a head H3. The lug ll is formed onan upstanding central boss IS on the follower C. The follower C is further provided with an outwardly opening, central seat 20, adapted to accommodate the usual spring centering projection, not

cylindrical friction surshown, of the bottom springplate of the truck spring cluster.

The shoe D is in the form of a transversely curved plate of substantially semi-cylindrical, transverse cross section and presents a lengthwise extending, transversely curved friction surface 2! on its outer side, which is in sliding engagement with the interio friction surface 13 of the casing, at the left hand side of the mechanism, as seen in Figure 1. At the upper end, the shoe D has a laterally outwardly projecting stop flange 22 overhanging the stop shoulder H) of the casing B to limit longitudinal separation of the casing and this shoe. On' the inner side of the shoe D, at the upper end thereofli a horizontally extending flange 23, which is in transverse alignment with the flange 22. At the lowerend thereof, the shoe D is'provided' with a relatively heavy, inturnedflan'ge 24, which is-engagedbethe right hand side of the mechanism, as seen:

in Figure 1. At the upper end, theshoe Eds provided with a. horizontal, laterallyinwardly'pro- J'ecting flange 26 engaged beneath the flange 23 of the shoe D. The shoerEis' shorter than the shoe D and has its lowerend spaced'from-theboss IQ of the follower C in the expanded .con-

dition of the mechanism. An inturned stop flange 825 at the bottom end of the shoe D, which is engaged beneath the head H! of the lug 1?, limits upward displacement of the shoe E.

.Therubber block-F is in the form of an elongated: cylindrical plug. The block F is interposedbetween the shoes D'and'Eand has flattened:top andrbottom end faces 21 and 28-bearing .respectively. on the underneathv sideof the' flange 26 of the shoe Ev and the top side=of the head-18 of the: lug H of the bottomfollower-C. The block F is under initial compression between thershoes l2), and E. and holds the same spread apart -intig ht-frictional.contact with the frictionsurface is of the casing B;

The spring G comprises a relatively heavy helical: coil surrounding the casing 13' and bearing at its top and-bottom ends, respectively, on the underneath side'of the top follower 'A and the top side-of the :bo-ttoin follower C. This spring is preferably under initial compression.

In assembling'the mechanism, with the casin 13: supported in inverted position; that is, with the follower A resting on a support and the casing upstanding therefrom, the spring G is placed over the casing "B in position resting. on the follower.- A; The assembled unit, comprising the two shoes Dand-E and the block F, in inverted position, is then engaged within the open end of the casing B, the shoe D being tilted inwardly this art,- m -improved-v shock absorber is substituted-for one or more of, the spring units-f a cluster of truck springs of a railway car and cooperates: with the -,top 'and-bottom'spring follower plates of such a cluster.

Inthe operation of my improved shock absorber, uponthesprings of the cluster-of the trucki-ofa railway car being. compressed the casing B is forced downwardly with the top spring follower plate of the clustentoward the bottom follower -C,;therebyqslidingthe shoes inwardly of the casing opposed by the spring G, thus; snubbing the action-of thetruck springs. As compressionof the shockabsorber-progresses,

- the lug E6 of the 'casing B, comes into contact with. the shoeE; forcing thesame, downwardly in. unison with. the. casing and compressing the rubberrblock 'F' in lengthwise directiongagainst the iower'follower- C, causing the-block to spread radially :and placing the shoes .-"l) ;and 1E. under progressively increasing additional pressure. The frictional resistance between the shoe D and casing B is thus greatly increased during the last part of the compression stroke of the mechanism, thereby correspondingly increasing the snubbing capacity of the same. Compression of the'shock absorber is positively limited by engagement of the lowerend of the casing B with the follower 0.

Upon recoil of the truck springs, the actuating pressure on thefollower A is reduced, thus pervmitting the return of the parts to the normal position shown in Figure 1, by the expansive action of. the spring G and the resilient rubber '7 block F.

I claim:

1. In a shock absorber, the combination with a friction casing; of a pair of friction shoes slidingly-telescoped within the casing; a follower, said casing and follower being relatively movable toward and away from each other: lengthwise of the mechanism; one ofsaid-shoes beinganchored to :the fol-loweriand -h'eld against: relative lengthwise movement with respect to said followers; and the 1 other -shoe rbeing movable-lengthwise with respect to saidfollower; yielding ,means :between said follower. and: casingrropposingv lengthwise movement of said: follower; andicasing' to-ward each. other; :a. rubber block interposed-between said shoes; said block.being'underalaterai compression between said 511065;;2J1dzb62t1il'lg at opposite ends on said fol-lowerandrshoe whichyis movable withrespectto said follower foropposing relative movement: of said follower. and :last namedshoe 'towardeach other; and a shoulder on said casing engageable with said last na-med shoe after compression of the mechanism tora predetermined extent. for moving said .zshoetoward said follower to compress said resilient rubber means lengthwise :and expandthe same laterally against said shoes.

2. Ina shockiabsorber, the;combinationvwith an end follower; ofia second-end fol-low'erhaving a retaining lug thereon, said followers being'movable toward eachiother lengthwisezof the mecha nism; a friction casing projecting fromzsaid first named follower toward said-secondnamedfollower; a friction shoe having a flange in looking engagement between saidsecond named follower and the retaining lug thereof; a second friction shoe-movable toward and away, from saidsecond"namedi'follower, said shoes being. slidingly telescoped within the-casing;"a rubber element interposed betweensaid shoes and-opposing relative movement of; saidisecond named shoe and second named follower toward each other,: said rubber element being 'under lateral compression between said'shoes; :forholding the-latter spread apart; yielding means;between-saidfollowers opposing movement. of said followers toward each other; and means on said: casin engageable with said second named shoe after compression {of the mechanism to...aswpredetermined extent-for moving said second namedzshoe lengthwise with respect to said second named follower, compress- .ing said rubber ;,elementyin lengthwise direction.

3.,v In ashock absorber,.the combination witha follower at oneend of the mechanism;- of a second follower at. theother end of the mechanism, said followers being-relatively movable toward and away from each other; a .f-riction. casing projecting from said first named follower,.. said casing being rigid with .said follower; an inwardly extending lug on said second named-follower; 2581i]. 1112 :llaving-a headv atits-outer endpa frictionshoe having a retaining flange at its outer end engaged and fitting between said second named follower and head of the lug thereof; a second friction shoe, said shoes being slidingly telescoped within the casing, said second named shoe being movable lengthwise with respect to said second named follower; a rubber pad under lateral compression interposed between said shoes, said pad bearing at one end on said head of the lug of said second named follower; an inturned flang at the inner end of said second named shoe bearing on the other end of said rubber pad; an interior shoulder on said casing engageable with said second named shoe after compression of the mechanism to a predetermined extent for forcing said second named shoe lengthwise toward said second named follower to compress said pad in lengthwise direction; and spring means between said followers yieldingly opposing relative movement of said followers toward each other.

4. In a shock absorber, the combination with a follower having a post projecting therefrom, said post having an annular retaining flange at its outer end; of a friction casing, said casing and follower being relatively movable toward and away from each other; a pair of friction shoes slidingly telescoped within the casing, each of said shoes having a retaining flange at its outer end engaged in back of said retaining flange of the post, one

ill

of said shoes having the outer end thereof engaged with said follower and the other of said shoes having the outer end thereof normally spaced from said follower, said last named shoe having an inturned abutment flange at its inner end; an interior lug on said casing normally spaced from the inner end of said last named shoe and engageable therewith after the mechanism has been compressed to a predetermined extent to force said shoe toward said follower; a rubber block between said shoes, said block bein under lateral compression between aid shoes and under lengthwise compression between said inturned flange and the post of said follower; and spring means between said casing and follower yieldingly opposing relative movement of said casing and follower toward each other.

GEORGE E. DATH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,360,484 OCoonor Nov. 30, 1920 2,220,074 Blattner Nov. 5, 1940 2,242,413 Blattner May 20, 1941 2,379,078 Haseltine June 26, 1945 

